1. Field of the Invention
The present invention relates to an in-vehicle navigation device for guiding driving of a vehicle and in particular to an in-vehicle navigation device for guiding driving of a vehicle running on an expressway.
2. Description of the Related Art
Among in-vehicle navigation devices proposed in the related art there is a device that performs a search, while the vehicle is running on an expressway, for facilities which are located within a specified distance from a next exit of the expressway and facilities which are located along a guiding way and within a specified distance from the vehicle to display them. The in-vehicle navigation device proposed in the related art has a configuration including: a vehicle position detection unit for detecting the present position of the vehicle; a map data storage unit for storing map data including exits of expressways and facilities; a facility search unit that searches facilities located within a predetermined distance from the next exit of the expressway from the map data on the basis of the vehicle position detected by the vehicle position detection unit while the vehicle is running on an expressway; and a display unit for displaying the facilities searched by the facility search unit. According to this configuration, it is possible to search, while the vehicle is running on the expressway, facilities that can easily be reached from the next exit of the expressway and to display the facilities (for example, see patent document 1).
[Patent Document 1] Japanese Unexamined Patent Publication No. 2001-21376 (paragraph numbers [0001], [0015], [0016])
However, in the above mentioned in-vehicle navigation device proposed in the related art there is a problem that the device can not search a guiding route of the vehicle on which the vehicle returns again to the expressway from a target facility after it reaches the target facility from the exit of the expressway. Since Japanese expressways are available on a chargeable basis, there are hardly cases where a user driving on an expressway utilizes a facility, such as gas station outside the expressway and then again returns to the expressway from the facility. On the other hand, expressways in foreign countries such as European countries and U.S.A. are available on a free of charge basis in addition they have facilities, such as rest rooms but they rarely have facilities of gas station and shops unlike expressways in Japan. For this reason, in countries where expressways are available on a free of charge basis, there are extremely common cases where even if a driver runs on an expressway, the driver utilizes a facility outside the expressway and again returns to the expressway.
Moreover, even in Japan, a fact that public expressways utilized by a large number of vehicles are available on a chargeable basis has become a social problem, so it is sufficiently possible thought that the public expressways will be available on a free of charge basis in future. If the public expressways become available on a free of charge basis, just as with European countries and U.S.A., there are sufficiently possible cases where a driver utilizes a facility outside the expressway and then again returns to the expressway.